Quartiles

Quartiles split a set of data into four equal parts. 25.0% of the values are smaller than the first quartile, Q1, and 75.0% are larger. The second quartile, Q2, is the median. 50.0% of the values are smaller than the median and 50.0% are larger. 75.0% of the values are smaller than the third quartile, Q3, and 25.0% are larger.

The quartiles are defined in Equations (4.3) and (4.4).

First Quartile Q1

The first quartile Q1, is the value such that 25.0% of the values are smaller and 75.0% are larger.

Equation 4.3

where n = sample size

Third Quartile Q3

The third quartile Q3, is the value such that 75.0% of the values are smaller and ...

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